Scarlett Johansson at the Marvel Avengers Assemble European Premiere at the Westfield Centre, London

Golden Globe nominee Johansson, 27, blossomed in a black and scarlet floral corset and lace skirt by Prada with bright red heels, while the Canadian actress, 30, lived up to her name in a red creation by New York designer Alexandra Vidal.

Johansson said she enjoyed reprising the role of the feisty Black Widow, originally seen in Iron Man 2, despite the injuries she suffered doing her own stunts.

“It’s nice to be able to play a female character that’s not a damsel in distress or some woman in waiting but to actually play someone who’s got a lot of conviction and who is really ready to kick some booty,” she said.

“It was just all one big injury the whole thing - you get used to it I guess.”

Smulders added: “It’s been a dream role for me. I love it.”

Downey Jr said it was “a blast” to be in London, saying: “It’s been five years since our last adventure so I’m happy and humbled to be here.”

Avengers Assemble, which also stars Samuel L Jackson and Gwyneth Paltrow, opens in cinemas on April 26.

“Where to go for a drink near Great Portland Street?” was previously met with blank expressions and shrugs for those local to the area, not anymore, thanks to the opening of The Refinery at Regent’s Place, the eighth bar and restaurant from hugely-successful group Drake & Morgan.